GO2-83-111, Revised Final Deficiency Rept,Condition 51 Re Nonseismic Class 1 Digital Electrohydraulic Cabinets.Initially Reported on 810624.Reanalysis Concluded That Digital Electrohydraulic Cabinets Cannot Fall Over During DBE

Revised Final Deficiency Rept,Condition 51 Re Nonseismic Class 1 Digital Electrohydraulic Cabinets.Initially Reported on 810624.Reanalysis Concluded That Digital Electrohydraulic Cabinets Cannot Fall Over During DBE

ML20083B630
Person / Time
Site:	Columbia
Issue date:	12/02/1983
From:	Sorensen G, Sorenson G WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
10CFR-050.55E, 10CFR-50-55E, 10CFR-50.55E, 51, GO2-83-1113, NUDOCS 8312210232
Download: ML20083B630 (2)

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e Washington Public Power Supply System P.O. Box 968 3000 GeorgeWashington Way Richland, Washington 99352 (509)372-5000

!.5 December 2, 1983 :n A G02-83-lll3 !O F3 7

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Mr. J. B. Martin 9_

Regional Administrator M U.S. Nuclear Regulatory Commission Region V 1450 Maria Lane, Suite 210 Walnut Creek, Ca'lifornia 94596

Subject:

NUCLEAR PROJECT NO. 2 10CFR50.55(e) REPORTABLE CONDITION #51 NON-SEISMIC CLASS I DEH CABINETS - REVISED FINAL REPORT

Reference:

Letter G02-81-0155, dated June 24, 1981, R. G. Matlock to R. H. Engelken.

In accordance with the provisions of 10CFR50.55(e), your office was trans-mitted a Final Report on the above condition via the reference. The cor-rective action committed to in that report, installation of a steel frame to prevent toppling of the DEH cabinet during a seismic event, has been determined to be unnecessary. The attachment provides the Project's revised Final Report.

If you have any questions regarding this subject, please contact Roger Johnson, WNP-2 Froject QA Manager, at (509) 377-2501, extension 2712.

J ho-G. C. Sorensen Manager, Regulatory Programs RTJ/kd Attachment- As stated cc: W.S. Chin, BPA N.D. Lewis, EFSEC A. Toth, NRC Resident Inspector Document Control Desk, NRC 831221v2.1 831202 PDR ADOCK 05000397 S PDR ,

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WASHINGTON PUBLIC POWER SUPPLY SYSTEM NUCLEAR PROJECT NO. 2 DOCKET NO. 50-397 LICENSE N0. CPPR-93 10CFR50.55(e) CONDITION #51 NON-SEISMIC CLASS 1 DEH CABINETS FINAL REPORT (REV. 1)

Description of Deficiency The digital electro-hydraulic (DEH) control system for the turbine-generator is a Quality Class II system. Regulatory Guide 1.29 requires that such sys-tems should be designed and constructed so that a seismic event would not cause them to fail and impair the function of safety-related systems. The DEH cabinets are located in the control room, but have not been designed, manufactured, or installed to Seismic Category 1 requirements.

Safety Implications Failure of the DEH cabinet structure or supports during a seismic event could cause damage to safety-related equipment located in the Reactor Centrols Bench Board mounted directly in front of the DEH cabinet. Damage to the safety-re-lated equipment could result in the loss of ability to safely shut down the

plant. In addition, DEH cabinet failure may do bodily harm to Control Room personnel who may be in the immediate area.

Corrective Action Dynamic tests were performed on the DEH cabinets to determine their response freouencies. These tests demonstrated that the cabinets respond as essen-tially rigid structures. The cabinets and supports were then reanalyzed for equivalent horizontal and vertical static loads obtained from applicable re-sponse spectra, at the cabinet response frequencies. This reanalysis con-cluded that the DEH cabinets cannot fall over during the design basis safe shutdown earthquake (SSE). Therefore no physical restraints to prevent top-pling of the cabinets are required.

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